Danger: Dinosaurs! by Richard Marsten--_A treacherous big-game hunter leads an expedition back to the Age of Reptiles_ Earthbound by Milton Lesser--_An ex-space cadet is forced to plunder ships he was trained to protect_ Find the Feathered Serpent by Evan Hunter--_Explorers in Mexico discover startling Mayan remains_ Five Against Venus by Philip Latham--_A Moon-bound rocket crashes in the misty wilds of Venus_ Islands in the Sky by Arthur C. Clarke--_A teen-ager's adventures aboard a space station_ Lost Planet, The by Paul Dallas--_Two worlds on the verge of war_ Marooned on Mars by Lester del Rey--_A teen-ager on the first Moon-to-Mars expedition_ Missing Men of Saturn by Philip Latham--_A space crew is held prisoner by froglike men on Saturn_ Mission to the Moon by Lester del Rey--_Scientists make man's first journey to the Moon_ Mists of Dawn by Chad Oliver--_A space-time machine hurls a 20th-century boy back to 50,000 B. C._ Mysterious Planet, The by Kenneth Wright--_A young captive on Planet X prevents Earth's destruction_ Mystery of the Third Mine by Rob. Lowndes--_Prospecting in the dangerous Asteroid belt_ Planet of Light by Raymond F. Jones--_A trip to another planet shows how the Universe can be saved from destruction_ Rocket Jockey by Philip St. John--_A space pilot battles Martians in rocket race_ Rocket to Luna by Richard Marsten--_A stowaway on a Moon-bound rocket proves his worth_ Rockets to Nowhere by Philip St. John--_Scientists establish a colony on the Moon_ Secret of Saturn's Rings, The by Donald A. Wollheim--_A scientist proves his theories by means of a unique invention_ Secret of the Martian Moons, The by Donald A. Wollheim--_Scientists discover the secrets of Martian civilization_ Son of the Stars by Raymond F. Jones--_An interplanetary friendship brings Earth to the brink of destruction_ Sons of the Ocean Deeps by Bryce Walton--_Undersea terrors nearly thwart a project aimed at saving a continent_ Star Seekers, The by Milton Lesser--_A tale of a spaceship doomed to crash_ Step to the Stars by Lester del Rey--_The U. S. builds a space station_ Trouble on Titan by Alan E. Nourse--_A rocket experimenter discovers a plot threatening Earth's existence_ Vandals of the Void by Jack Vance--_A tale of space pirates_ Vault of the Ages by Poul Anderson--_Life 500 years after the flaming collapse of 20th-century civilization_ World at Bay, The by Paul Capon--_Men from another planet attack Earth_ _The year When Stardust Fell_ By RAYMOND F. JONES--A Mysterious "Fall-Out" Paralyzes Civilization Mayfield was the typical college town. Nothing too unusual ever happened there until a mysterious comet was suddenly observed by the scientists on College Hill. And then one day the modified engine on Ken Maddox's car began overheating mysteriously. By morning it didn't run at all.